1. Field of the Invention
The present invention relates to a magnetic head slider used for a magnetic disk drive.
2. Description of the Related Art
In a head slider for a magnetic disk drive in recent years, a reduction of floating amount for increasing the recording density has been under way. In Fun addition, since a high acceleration is applied in the access direction for enhancing the speed of access, there is a demand for a head slider excellent in stability of floating. Furthermore, a rotation type positioner is widely used for reducing the drive in size and simplifying mechanism, and there is a request for a head slider with less variation of floating amount due to variation of yaw angle.
In order to reduce the floating amount of the head slider, it is necessary to reduce the surface roughness of the magnetic disk surface. In the contact-start-stop (CSS) system widely used until now, the floating surface of the magnetic head slider and the magnetic disk make contact with each other at rotation stop times of the magnetic disk, and the magnetic head slider is floated by the action of the airflow generated attendant on the rotation of the magnetic disk at rotation times of the magnetic disk. Therefore, in the magnetic disk drive of the CSS system, if the surface roughness of the magnetic disk is reduced, the contact area between the floating surface (air bearing surface) of the magnetic disk slider and the magnetic disk surface at the rotation stop times of the magnetic disk is enlarged, so that there may be a risk of stiction occuring between the magnetic head slider and the magnetic disk when the magnetic disk drive starts rotation.
In the magnetic disk drive of the CSS system, in order to obviate the stiction trouble, a technique of texturing the CSS zone of the magnetic disk by laser and a technique of providing the slider floating surface with a plurality of pads (projections) have been proposed. On the other hand, portable personal computers such as notebook-type personal computers are frequently carried and, therefore, are required to have high shock resistance. Therefore, a magnetic disk drive of the loading-unloading system in which the head slider is unloaded from the surface of the magnetic disk at power off times and sleep mode times and is loaded into the position above the surface of the magnetic disk at use times is generally adopted.
In the magnetic disk drive of the loading-unloading system, a cornual portion provided at a tip end portion of a suspension is caused to ride onto a ramp (inclined portion) of a ramp member provided at an outer peripheral portion of a disk medium at power off times or sleep mode times of the computer, whereby the magnetic head slider floating above the magnetic disk with a minute gap is removed from the position above the magnetic disk. By this, it is possible to prevent the magnetic head slider from knocking on the magnetic disk, thereby damaging the magnetic disk, when a shock is exerted on the computer.
The magnetic head slider used for the magnetic disk drive having the loading-unloading mechanism is required to have such high reliability that the contact or collision of the magnetic head slider against the magnetic disk is prevented not only when the magnetic head slider is floating above the magnetic disk but also when the magnetic head slider is loaded into the position above the magnetic disk. In order to reduce the floating gap of the magnetic head slider relative to the magnetic disk, a negative pressure magnetic head slider is often used for the recent magnetic disk drives. For example, Japanese Patent Laid-open No. 2000-173217 discloses a negative pressure head slider with low floating amount, little variation of floating amount and high rigidity.
As a prior art for reducing the floating amount of the magnetic head and lowering the magnetic spacing, Japanese Patent Laid-open No. 2000-348321 discloses a conventional technique of embedding a piezoelectric element in the back surface of the magnetic head slider as shown in FIG. 1. FIG. 2 is an illustration of operation of the prior art example shown in FIG. 1. As shown in FIG. 1, the magnetic head slider has an air inflow end 2a and an air outflow end 2b, and an electromagnetic transducer 4 is provided in the vicinity of the air outflow end 2b. 
A laminate-type piezoelectric actuator 6 is embedded on the air outflow end side of the back surface 2c of the magnetic head slider 2. Numeral 8 denotes electrodes of the piezoelectric actuator 6, and a voltage V is applied between the adjacent electrodes 8. As shown in FIG. 2, when the voltage V is applied between the adjacent electrodes 8, the piezoelectric actuator 6 is displaced in the direction of arrow 10. Numeral 11 denotes a magnetic spacing direction, and 12 denotes the transducer displacement direction. Numeral 14 denotes an air bearing surface (ABS) on the air outflow end side, and 16 denotes a recording medium.
In the magnetic head slider 2, as shown in FIG. 2, the displacement direction 10 of the piezoelectric actuator 6 is the rotational direction of the recording medium 16, and the floating amount is regulated through deflection of the slider 2 by displacement of the piezoelectric actuator 6, so that the displacement direction 12 of the electromagnetic transducer 4 is varied according to the displacement amount of the piezoelectric actuator 6. With the piezoelectric actuator 6 driven, the electromagnetic transducer 4 is inclined, so that there is the problem that the electromagnetic transducer 4 does not come to the lowermost point of the slider 2 and the floating amount is unintentionally enlarged, and there is also the problem that time variation (jitter) of recording and/or reproduction is enlarged.
In addition, elongation of the piezoelectric actuator 6 leads to deflection of the air outflow end side ABS 14, resulting in the electromagnetic transducer 4 being brought near to the recording medium 16. However, there is the problem that the positive pressure generated by the air outflow end side ABS 14 is enlarged and the floating amount is rather enlarged. In order to solve these problems, Japanese Patent Laid-open No. 2000-348321 proposes a magnetic head slider comprising a slider main body, a piezoelectric element fixed to the slider main body, and a block having an electromagnetic transducer fixed to the piezoelectric element. However, this magnetic head slider is complicated in structure and suffers the problem that it is difficult to manufacture.